WWII US Naval dictionary, Glossary, Terminology, Jargon and Phrases

Note: The majority of terminology below refers primarily to the U.S. Navy and/or to U.S. submarines. Several items, however are specific to both U-boats and the German Kriegsmarine and are so noted.

AA - Anti aircraft

AAF - US Army Air Forces

Abaft - Toward the stern of a boat or a ship.

Abaft the beam - Any direction between the beam and the stern

ABDACOM - American/British/Dutch/Australian Command

Abeam - A position 090° or 270° relative to the ship's heading.

Acey deucy - Sailors version of backgammon

Acoustic Torpedo - A torpedo that dtects its target by means of sound, and uses that sound to steer along its path.

ACR - Anti Circling Run device

Admiralty - A body of law that deals with maritime cases.

Adressbuch - (Kriegsmarine) U-Boat codebook used in diguising ocean chart grid positions in radio transmissions.

Advance - The distance gained in the original course when turning.

Aft - A position to the rear or the rear extremity of a given object.

After Trim - Variable ballast tank used to adjust the a submarine's weight and tilting movement.

Air Banks -Groups of large air bottles located in midship ballast tanks to store high pressure air for charging torpedoes, blowing tanks, and other services.

After Battery Compartment - Main section of the submarine behind the control room; houses battery cells and crew living and dining spaces.

AIB - Allied Intelligence Bureau

Air Gap - The Mid Atlantic region that, until 1943, was not covered by British and/or American ASW aircraft.

Air Manifold - A series of valves through which compressed air at 600 psi can be fed into tanks at reduced pressure.

Alarm! - Emergency dive order on a U-Boat.

Amps a side - A measure of motor speed by means of current consumption on older types of boats.

Amtrac - Amphibious tractor, used to ferry troops in a landing assault ashore

Anchor Watch - Detail of hands standing by as a readiness precaution while the ship is in port.

Angle on the Boat - The angle of the keel from horizontal

Angle on the Bow - The angle between the fore-and-aft axis of the target and the Line of Sight (LOS), measured clockwise from the target's bow to starboard (right) or port (left).

Annunciator - An electro mechanical signaling device for sending orders to the engine room.

AO - Oil tanker

AP - Troop transport ship (non-landing)

APR 1 - Non directional radar detector.

Aphrodite - German device used to confuse radar by reflecting impulses.

Armed Guard - US Navy gun crews serving aboard a merchant ship.

Ash Cans - Depth charges

Astern - A position or location behind the ship.

A Scope - A viewing screen of the surface search radar.

ASDIC - Acronym for the British Anti-Submarine Detection Investigation Committee; the name given to a device housed under the hull of an anti-submarine vessel and used in detecting the presence of submerged submarines.

ASV - Airborne microwave radar (10 and 3 cm)

ASW - Anti-Submarine Warfare.

Athos - Radio detection antenna

Athwartships - Direction 90° relative to the fore and aft reference meaning across the ship.

Awash - Condition whereby the seas are flowing over the surface of an object as in decks awash.

Auxiliary Tanks - Variable ballast tanks located amidships and used to obtain neutral buoyancy and adjust trim; one tank generally segregated for storing fresh water.

Azimuth - The bearing of an object from the observer measured as an angle clockwise from true north.

AVG - American Volunteer Group (Flying Tigers)

Bachstelze - (Kriegsmarine) water stilt - auto-gyro like device towed on a cable behind a U-Boat to improve the field of vision of the "flying lookout".

Backwash - Water thrown aft by the turning of a propeller.

Bali - A radar detection aerial.

Ballast - Heavy weight in the hold of a vessel to maintain proper stability, trim or draft.

Ballast Tanks - Sections of the space between the pressure hull and the outer hull, and saddle tanks within the torpedo rooms; blown dry to provide positive buoyancy when the submarine is surfaced and completely flooded to give neutral buoyancy when submerged.

Banca - Small native outrigger

Barge - A craft used to haul materials. Also a motorboat assigned as transportation for Admirals.

Base Course - A reference course or direction desired to be made good when evasive steering is being carried out.

Battalion - (USMC, US Army) Usually about 400-strong, is comprised of three rifle companies, a combat support company and a headquarters company.

Battery Fresh Water Tanks - Storage tanks for the distilled water used in watering the main storage batteries.

Bathythermograph - A device to record sea temperature and submarine depth and to show any abrupt temperature change or gradient.

Battle Surface - A surfacing operation during which the submarine is made buoyant by blowing tanks and then held down by the bow and stern planes and motor power until she leaps forward. Boats thus handled come up flat, or nearly flat and suddenly enabling quick deployment of gun crews.

Battle Lights - Dim red lights that furnish sufficient light for personnel during darken ship period.

Bay of Biscay - The Atlantic bay between northern Spain and northwestern France.

BB - Battleship (USN)

BD - Battleship Division (USN)

B-Dienst - (Kriegsmarine) Funkbeobachtungsdienst - German radio monitoring and crytographic intelligence service.

BdU - (Kriegsmarine) Befehlshaber der Unterseeboote - Commander in Chief, U-Boats; referred specifically to Admiral Karl Dönitz, but also in reference to his staff and headquarters.

Beam - Measured dimension of a ship at its widest part.

Bearing - Used to define the direction of an object or a course from a particular point.

Bee - U-Boater nickname for aircraft

Bed Pan Commando - Slang nickname for US Navy Pharmacists Mates

Bell Book - A log containing the entries of the various speed and direction orders sent to the engine room.

Bendix Log - An underwater device for measuring own ship's speed.

Betty - Japanese patrol bomber or torpedo plane.

Bilge - Lower part of the vessel where waste water and seepage collect.

Billet - Allotted sleeping space; A man's position in the ship's organization.

Black gang - Slang for engine room crew.

Blackout - A darkened ship.

Bleed in - To let in a small, controlled amount of air or water.

Bletchley Park - The British Government Code and Cipher School, located in a large country house in Buckinghamshire, north of London England.

Blister - Armored bulge in a warship's side as protection against torpedoes.

Blow Ballast - To force water from tanks into the sea with compressed air.

Bluejacket - A Navy enlisted man below the grade of CPO; a "white hat."

Boatswain - A sailor whose main duties pertain to deck and boat seamanship. Pronounced bosun.

Bogey - Unidentified (pssibly enemy) aircraft

Boiler - Synonym for pigboat, sewer pipe, submarine

Bold - (Kriegsmarine) Device used by U-Boats to confuse ASDIC

Boot - Slang for a US Navy recruit or leggings.

Boot - (Kriegsmarine) A German boat or warship; the commander is a non staff officer, and the second in command is called the First Watch Officer, i.e. on a submarine.

Bootskanone - (Kriegsmarine) The gun on the foredeck of a U-Boat.

Bow - Forward end of a vessel

Bow Buoyancy - An additional ballast tank to provide extra buoyancy forward when surfacing or in an emergency situation.

Bow Caps - small doors on the outside ends of a submarine's torpedo doors.

Bow Planes - The pair of horizontal rudders at the submarine's bow, rigged out on diving to help give initial down angle, then used in coordination with the stern planes to control depth.

Brag Rags - Miniature Japanese flags displayed on the conning tower or flown from the periscope shears of WWII US submarines indicating the number of enemy vessels sunk.

Bridge - A raised platform from which a ship is steered, navigated or conned.

Brig - Prison on a ship or shore base.

Brigade - (USMC, US Army) Consists of approximately 2,500 persons commanded by a colonel. The brigade provides mobility, counter-mobility and survivability, topographic engineering and general engineering support to the largest unit - the corps, and augments various divisions. The brigade may contain combat engineer battalions, separate engineer companies, assault float bridges, and topographic and tactical bridge companies.

Broach - The act of breaking through the surface and rising out of the water, sometimes called porpoising.

Broadside - Firing ship's armament or receiving hostile fire perpendicular to the ship's course.

Brow - A gangplank, ladder or walkway leading from the ship to the pier.

BuOrd - (Bureau of Ordnance) Navy Department responsible for weapons and ordnance.

BuPers - (Bureau of Personnel) Navy Department responsible for personnel (Formerly BuNav)

BuShips - (Bureau of Ships) Navy Department responsible for construction and maintenance of naval ships.

Bulkhead - Traditional nautical term for a wall or partition on a ship.

Bulwarks - A structural extension of a ship's sides above the upper deck.

Bunkers - Storage space for fuel (US) or the exterior fuel tanks on a U-Boat

CA - Heavy Cruiser (USN)

Can - Storage batteries.

CAP - Combat Air Patrol (USN)

Capital Ship - A term used throughout WW II to define the most significant warships in a fleet.

Captain - The officer rank between Rear Admiral and Commander (USN). Also a naval officer commanding a warship.

Casing - A submarine's outer skin of light plating which encloses the ballast tanks and pressure hull.

Cast - US cryptanalysis unit (Cavite, Manila Bay)

Cavitation - The formation of a partial vacuum and resulting air bubbles around rotating propeller blades; the collapse of this vacuum creates propeller noises.

CBI - China-Burma-India; operational area for Allied forces in WW II

CD - Cruiser Division (USN)

Chidori - Japanese anti-submarine vessel; a type of torpedo boat

Chief of the Boat - A petty officer in charge of enlisted personnel; generally one of the most experienced of the enlisted men on board.

Chopline - Change of Operational Control (See MOMP)

Christmas Tree - Panel of red and green lights which denote whether valves and vents are open or closed.

Chutai - Japanese word for "squadron"

CIC - Combat Information Center (USN)

Cigarette Deck - The open, railed platform aft of a US fleet submarine's bridge. Similar to a U-Boat's wintergarten.

CinCLant - Commander in Chief, Atlantic Fleet (USN)

CinCPac - Commander in Chief, Pacific Fleet (USN)

Cipher - A secret letter substitution communication coding system.

CL - Light Cruiser (USN)

Clamp Down - Go over the living space decks with a damp swab.

Class - Vessels of the same type built to a common basic design.

Clinometer - Bridge and engine room instrument that indicates the amount of a ship's roll or degree of list.

CNO - Chief of Naval Operations (USN)

Coaming - Raised framework around deck or bulkhead openings and cockpits of open boats to prevent the entry of water.

CO - Commanding Officer (USN)

COMINCH - Commander in Chief, United States Fleet. (USN)

Commander - The officer rank between Captain and Lieutenant Commander (USN).

Company - (USMC, US Army) Consists of 130 to 150 soldiers or Marines. Normally commanded by captains and consisting of two or more platoons, usually of the same type, a headquarters unit and some logistical capabilities. Companies are the basic elements of all battalions.

Compensation - The process of transferring ballast, in the form of water, between the variable tanks, and between the variable tanks and sea, to effect the desired trim.

ComSubDiv - Commander Submarine Division (USN)

ComSubPac - Commander Submarine Force, Pacific (USN)

ComSubRon - Commander Submarine Squadron (USN)

ComSubSoWesPac - Commander Submarine Force, Southwest Pacific (USN)

Collision Bulkhead - The foremost transverse watertight bulkhead in a ship that extends from the bottom of the hold to the main deck.

Condenser - Device for converting exhaust steam from engines into water for re-use.

Conn - The authority directing the steersman, or the act of directing and thus maneuvering the ship.

Conning Tower - The small, heavily armored horizontal hull directly above the control room and below the bridge. Houses the normal steering stand, torpedo data computer (TDC), firing panel, surface search radar, periscopes, sound receivers (except sonic JP), fathometer, navigational plot, and receivers from the target bearing transmitters (TBT); in essence. the heart of both the ship and the torpedo fire control.

Contact Pistol - Torpedo detonator that explodes upon striking a solid object; also called a contact fuse.

Control Room - The midship compartment containing all diving controls, the ship's gyrocompass and its auxiliary, the air search radar, an auxiliary steering stand, the interior communications switchboard and the radio room.

Convoy - A precise assembly of merchant ships organized in columns and escorted by warships.

Corps - (USMC, US Army) The corps is the largest tactical unit. The Corps is responsible for translating strategic objectives into tactical orders. It synchronizes tactical operations including maneuvering, the firing of organic artillery, naval firing, supporting tactical air operations, and actions of their combat support, bringing together these operations on the battlefield. Each corps will have between two and five divisions, depending on the mission.

Corvette - A highly maneuverable armed escort ship, smaller then a destroyer.

Countermeasure - A device, tactic, or material designed to reduce the effectiveness of an enemy attack.

Course - Direction steered by a ship.

CPO - Chief Petty Officer USN)

Crash Dive - USN term for an emergency dive by a submarine.

CSF - Caribbean Sea Frontier (USN)

Cutie - Passive homing torpedo

CV - Aircraft Carrier (USN)

CVE - Escort Aircraft Carrier (USN)

CVL - Light Aircraft Carrier (USN)

Cypern - A type of radar detector.

D-Day - Day on which an operation is to commence and/or on which troops will depart (Day of Departure).

DD - US Navy designation for Destroyer

DE - Destroyer escort (USN)

Damage Control - Measures necessary to keep a ship afloat, fighting and in operational condition.

Davy Jones Locker - The bottom of the sea.

Day's duty - Tour of duty on shipboard lasting 24 hours.

Dead ahead - Directly ahead of the ship's bow; bearing 000° relative.

Deadweight tonnage - The difference between a ship's light and loaded displacement.

Deck Gang - Men of the ship's gunnery crew; all deckhands.

Deckhouse - An enclosed structure raised above the weather deck of a vessel.

Degaussing Gear - Electrical gear which sets up neutralizing magnetic fields to protect the ship from magnetic action mines or torpedoes. Pronounced de-gow'sing.

Depth Charge - Explosive charge used against submarines.

DesDiv - Destroyer Division (USN)

DesRon - Destroyer Squadron (USN)

Displacement - The weight of a boat or ship, as measured by the amount of water displaced when placing the vessel in water.

Disposition - An ordered arrangement of two or more formations proceeding together.

Distance to Track - The distance in yards to the target track, measured along a line perpendicular to the target track.

DivCom - Division Commander (USN)

Diving Trim - The condition of a submarine when it is so compensated (see compensation) that completing the flooding of the main ballast, safety, and bow buoyancy tanks will cause the vessel to submerge with neutral buoyancy and zero fore-and-aft trim.

Division - In an organization of ship groups: The unit between sections and squadrons; in shipboard operations: a number of men and officers grouped together for command purposes.

Division - (USMC, US Army) Divisions perform major tactical operations for the corps and can conduct sustained battles and engagements. One division is made up of at least three brigades with between 10,000 and 20,000 soldiers. Divisions are normally commanded by major generals. Types of divisions include light infantry, armored and mechanized infantry, airborne and air assault.

Doc - Nickname for personnel with a medical rank or rating (Doctor, Pharmacist Mate, Corpsman, Medic)

Dock trials - Four to six hour trial of main engines while the ship is moored alongside a pier.

Dogs - The pawls securing a watertight door or hatch.

Dog Watch - Normally the 1600 to 1800 and 1800 to 2000 watches, although any four hour watch may be halved or "dogged".

DR - Dead Reckoning position, obtained by using the ships course, speed and elapsed time.

DRI - Dead Reckoning Indicator; receives input from the Bendix Log and gyrocompass, and has dials indicating longitude and latitude.

Draft - The ship's vertical extension below the waterline at various points along the entire length measured in feet and inches. Traditionally measured at the stern, bow, and amidships.

Dräger Tauchretter - (Kriegsmarine) An underwater escape apparatus for U-Boat crewmen.

ECM- (Electric Coding Machine) Standard submarine coding - decoding device. When operating in shallow coastal waters the ECM was sometimes left behind to prevent its falling into enemy hands should the sub become sunk and salvaged; usually a simple strip cipher device was substituted for the ECM.

Echo Sounder - Fathometer; device for measuring the depth of water by sending out vibrations which bounce back from the bottom. It measures time taken for the echo to return, and from that the distance is calculated.

Eel - (Kriegsmarine) U-Boat nickname for a torpedo.

Encryption - Enciphered or coded message.

End Around - Submerged and surfaced maneuver to pass an enemy convoy and gain position ahead.

Engine Air Induction Valve- Large mushroom shaped valve to provide air to the diesels.

Engine Order Telegraph - Signaling gear for transmitting speed and direction from the bridge to the engine room.

Enigma - (Kriegsmarine) The Schussel M cipher machine also used in reference to the machine's encrypted message.

Escort - A ship or aircraft used to protect a merchant ship, main body, or convoy.

Escort Carrier - (CVE) Small aircraft carrier, usually built of a merchant ship hull, designed for anti submarine planes. (USN)

Ensign - Officer rank between Lieutenant (jg) and Chief Warrant Officer. (USN)

ESF - Eastern Sea Frontier (USN)

Expansion tank - Connected between the head box and the compensating water main, admits sea pressure to the fuel oil tanks. It receives any overflow from the fuel tanks resulting either from overfilling the fuel system or from temperature expansion. The bilges are pumped into this tank to prevent leaving an oil slick or polluting a harbor.

Eye Port - A small, thick glass window in watertight doors and also in the conning tower.

F-21 - The US Navy Atlantic Section, Intelligence Center, first called OP-20-G at Main Navy; an exact clone of the OIC submarine Tracking Room of the British Admiralty, it began operations in spring 1942.

FAT - (Kriegsmarine) Federapparat torpedo - An anti convoy torpedo employed by U-Boats that travelled in a straight line for a predetermine distance then zigzagged.

Fahnrich zur see - (Kriegsmarine) Midshipman

Fan - A torpedo spread.

Fantail - Term used to identify the stern deck area of a ship.

Fathom - Six feet or 1.829 meters

Fathometer - (See Echo Sounder)

FdU - ( Kriegsmarine ) Führer der Unterseeboote - Flag Officer for German submarines.

Fido - The "mine" MK24 torpedo

Field Strip - To disassemble without further breakdown the major groups of a piece of ordnance for routine or operating cleaning and oiling; as opposed to detailed stripping which may be done only by authorized technicians.

Final Trim - the running trim obtained after submerging, in which the fore-and aft and over-all weights have been so adjusted that the boat maintains the desired depth, on an even keel, at slow speed, with minimum use of the diving planes.

Fire Control - The mechanics of directing torpedoes or gunfire.

Fireman - Engine room crewman (USN)

Fish - U.S. submariner's nickname for a torpedo.

5ND - Fifth Naval District (USN)

Five by Five - Loud and clear (based on a system of indicating a radio's signal strength on a one to five scale).

500 Tonner - Type VII U-Boat

Fix - An accurate ship's position determined by obtaining star sights or bearings of known landmarks.

Flag Officer - An officer of the rank of Captain or above; so called because he is entitled to fly his personal flag which, by stars, indicates his rank.

Flak - Anti aircraft gun

Flank - Used in ship control language to indicate maximum speed ahead. also means aft starboard or aft port.

Flat - Description or state of a battery which has been discharged.

Fleet Type Submarine - Attack submarine used during WWII. Approx 250 were built between 1940 and 1945.

Flood Down - Fill tanks until the decks are awash.

Flood Valves - Large Kingston valves located in the bottoms of the ballast tanks to admit water; these valves were removed for wartime patrolling.

Flooding - Filling a tank through flood ports, open flood valves, or other sea connections.

Flotilla - Small fleet of small vessels.

Flotsam - General term for articles which will float when jettisoned. Floating debris left on the surface by a sunken ship.

Flugboat - German for flying boat aircraft.

FM Sonar - Sonar device used by US submarines to detect mines.

Foc'sle - Vernacular for forecastle

Foo Foo - Anything with a pleasant aroma noticeable after several weeks on patrol.

Foo Foo Dust - Talcum powder

Forecastle - A forward upper deck extending to the bow.

Formation - An ordered arrangement of two or more ships or units proceeding together.

Forward - Toward the bow; opposite of aft.

Forward Trim - Variable ballast tank used to adjust the submarine's weight and tilting movement.

Fox Schedule - (Fox Sked) Radio broadcast schedule of messages for U.S. submarines.

Foxer - British noisemaker towed behind ships to fool German acoustic torpedoes.

Fregattenkapitän - (Kriegsmarine) Captain - junior grade

Frontboot - (Kriegsmarine) U-Boat at sea that has entered an operational area.

Front Porch - Nickname for the 20 mm gun platform just forward of the bridge cowl on U.S. submarines.

FRUMEL - Fleet Radio Unit Melbourne (USN)

FRUPAC - Fleet Radio Unit Pacific (USN)

Fuel ballast tanks - Designed to be utilized as fuel oil tanks for increased operating range. When empty, they may be converted to main ballast tanks, providing additional freeboard and thereby increasing surface speed. (USN)

Full Speed - A prescribed speed that is greater then standard but less then flank.

Funk Telegraphie - (Kriegsmarine) FT - German reference to a wireless telegraphy radio transmission/reception.

Funker - (Kriegsmarine) Navy radioman

Funnel - A ship's smokestack.

G7a - German torpedo propelled by a compressed air system.

G7e - German battery driven torpedo.

Gaining Bearing - Catching up or drawing ahead when pursuing a ship.

Galley - A ship's kitchen.

Ganomie - A sea going Gremlin

Gangway - Any ladder or stairway providing ship to dock or ship to boat access.

Gas Boat - Gasoline driven submarines of the era before diesel engines.

General Quarters - Battle stations for all hands.

Going Hot - Torpedoes properly directed toward a target and as a matter of course, hitting.

GNAT - Name applied to the German T5 acoustic torpedo by the Allies.

GQ - General Quarters

Gradient - A layer, where the temperature of the sea water, and to a lesser degree its density, changes abruptly, thus sending sound waves of echo-ranging clear of a submarine below the layer.

Great Circle - Shortest route, following the arc of the earths surface.

Grossadmiral - (Kriegsmarine) Grand Admiral, corresponding to Fleet Admiral (USN).

Gross Ton - Measure of a ship's size based on volume: The internal volume of a ship (except passenger vessels) converted to tonnage based on one ton to 100 cubic feet.

GRT - Gross Register Tonnage; the total displacement of a ship.

Guide - In general, the ship on which other ships take station when forming, or keep station when formed up.

Gyro Angle - The angle between the fore-and-aft axis of your own sub and final track of the torpedo, measured clockwise from the bow of your boat; the angle set into each torpedo's gyro so that its steering mechanism will bring it to its proper course and hit the point of aim.

Gyrocompass - Compass used to determine true directions by means of gyroscopes.

Gyrocompass repeaters - Compass cards electrically connected to the gyrocompass and repeating the same readings.

Gyropilot - Automatic steering device connected to the repeater of a gyrocompass; designed to hold a ship on its course without a helmsman.

H-Hour - Time at which an operation is to commence

Hard Dive - Dive at maximum down angle

Hangfire - Gun charge that does not fire immediately upon pulling the trigger, but some time later.

Hatch - An opening in a deck.

HE - (Hydrophone effect) Underwater sound such as propeller cavitation by a surface ship or the path of a torpedo, detected by hydrophone and shown on instruments having a certain bearing or range.

Head - A compartment on the ship containing toilet facilities. Also the ship's stem.

Heel - to list over.

Hedgehog - A type of depth charge employed against U-Boats which were thrown ahead of the ASW ship. These devices were designed to explode on contact.

Hellsbells - name given to sound made by FM sonar.

Hellcats - Nickname for the group of US submarines equipped with FM sonar that conducted mine detection missions and/or penetrated the Sea of Japan (USN)

Hellpot - US nickname for Japanese mine

Helm - The mechanism for steering a ship; wheel or tiller.

HF/DF - (Huff Duff) High Frequency Direction Finder which allowed for the triangulation of the source of radio transmissions.

Higgins Boat - An amphibious landing craft (USN)

HMS - His/Her Majesty's Ship

HMAS - His/Hers Majesty's Australian Ship

Hold - Space below decks for storage of ballast, cargo etc.

Hull Down - Description of a ship beyond the horizon with only its masts or superstructure visible.

Hunter - Killer - A coordinated, aggresive anti-submarine operation by surface ships and/or air units to hunt out and destroy submarines.

Hydra - Cipher used by U-Boats in establishing the daily setting of the Enigma/Schlussel M cipher machine.

Hydrophone - Underwater sound detection device.

Hydroplanes - (see bow planes)

Hypo - US cryptanalysis unit (Honolulu, Hawaii)

I-Boat - Class of 2,100-ton displacement Japanese submarine.

IC - Interior Communications - Telephone or communications inside of a ship.

IC Switchboard - Interior Communications switchboard. Handles AC electricity for the gyrocompasses, TDC, interior communications as well as other uses.

ICOPA - Intelligence Center Pacific Ocean Area (US)

IJN - Imperial Japanese Navy

JAAF - Japanese Army Air force

Jam Air - To compress air

JANAC - Joint Army Navy Assessment Committee

Jetsam - Goods which sink when thrown overboard. Opposite of flotsam.

Jettison - The throw goods overboard.

JICPOA - Joint Intelligence Center Pacific Ocean Area

JK - (JK-QC)A dual head, passive/active sound device for supersonic frequencies (too high for the unaided ear).

JNAF - Japanese Naval Air Force

Joe - Coffee

JP - Passive, fixed head sound gear installed in mid 1944; An amplified sonic receiver.

Jumping Wire - Heavy cable with a cutting edge, stretched from bow to stern over the submarine's conning tower, to cut or deflect underwater obstacles like nets.

Kaleu, Kaleunt - (Kriegsmarine) Diminutive forms of the naval rank Kapitänleutnant.

Kapitänleutnant - (Kriegsmarine) Lieutenant Commander

Keel - Main longitudinal structure of the ship, located at the extreme bottom.

Keelhaul - To reprimand severely.

KIA - Killed in Action

Kingston - A valve from the bottom of the ballast tank to the sea.

Kiroshio - The Japanese current

Knot - A ship's speed measured as one nautical mile per hour.

Knuckle - A high speed turning maneuver which can return a solid sonar echo

Konteradmiral - (Kriegsmarine) Rear Admiral

Korvettenkapitän - (Kriegsmarine) Commander

Kriegsmarine - (KM) The German Navy 1935 -1945

Ladder Chancre